What is Mohs Micrographic Surgery?

Mohs surgery is a specialized treatment for the removal of skin cancer. This method differs from other methods of treating skin cancer by using complete microscopic examination of the cut tissue margin of the surgically removed tissue and detailed mapping techniques that allow the surgeon to track and remove all the roots and extensions of the skin cancer.

What are the advantages of Mohs Micrographic Surgery?

By using microscopic examination with detailed mapping, the Mohs surgeon can pinpoint areas involved with cancer that are otherwise invisible to the naked eye. Therefore, even the smallest microscopic cancer cells can be removed. The results are: 1) the removal of the smallest amount of normal skin as possible and, 2) the highest possible cure rate for the cancer.

What is the cure rate?

The cure rate with Mohs Micrographic surgery is greater than 99%. In the previously treated cancers in which the tumor is recurrent Mohs surgery is 95% effective.

For which type of cancers is Mohs Micrographic Surgery most useful?

Mohs surgery is most useful in treating skin cancers in cosmetically sensitive areas such as areas of the face, including nose, ears, eyelids and lip; or in treating skin cancers with a growth pattern associated with a high risk of recurrence.

The most common type of skin cancers treated with Mohs surgery are basal cell carcinoma and squamous cell carcinoma. Both tumors grow beyond what is seen on the skin’s surface and can extend along structures such as nerves, blood vessels and scars. With the Mohs technique, these extensions can be followed and removed. Melanoma is not commonly treated with Mohs surgery.

How is the surgery performed?

The area around the skin cancer will be cleansed and numbed using local anesthesia (typically the same anesthesia that was used for your biopsy). Once the area is numb, a small layer of tissue is removed. The tissue is carefully mapped and coded by the surgeon and taken to the adjacent in-house laboratory where the technician will immediately process the microscopic slides.

You will have a temporary bandage placed over the wound while you are waiting for the slides to be prepared.

The surgical procedure alone takes only 10-20 minutes. However, it takes a minimum of 45-60 minutes to prepare and microscopically examine the tissue. Several surgical stages and microscopic examinations may be required, and you will be asked to wait between stages. Although, there is no way to be certain, most cancers are removed in 3 stages or less.

What happens after the skin cancer is removed?

Immediately after the cancer is removed, a decision is made for the best method of repairing the wound created by the surgery. Most frequently, the wound is closed with stitches in a side-to-side fashion, by a skin graft, or by a skin flap. Occasionally, when the wound is small enough, no stitches are required, and the wound can heal on its own. Most patients will not require further procedures after the repair of the surgical defect. However, some repairs are completed in two stages, with the second stage occurring two to three weeks after the initial surgery.

Infrequently, a tumor may turn out to be much larger than anticipated. Under these circumstances, another specialist completes the reconstruction and it may take place on the same day or on a subsequent day. It is very rare that reconstruction may require hospitalization.

How long will the surgery last?

The length of surgery depends on the extent of the skin cancer. Often surgery lasts approximately a half day or longer. Much of your time is spent waiting for tissue to be processed. Bring reading materials, electronic devices (e-reader, iPad, tablet, etc.). Also, bring a snack or lunch with you on the day of surgery.

Will the surgery leave a scar?

Yes. Any form of treatment will leave a scar. However, because Mohs surgery removes as little normal tissue as possible scarring is minimized. Also, complete healing of the surgical site may appear red or may feel swollen or lump, particularly in the first few months. We recommend that the site be gently massaged beginning 4-6 weeks after the procedure.

Will I have pain after surgery?

Most patients do not have significant discomfort after surgery. Usually any pain after surgery responds to over the counter extra strength Tylenol (acetaminophen). You may have some swelling and bruising around the wound, especially if the surgery is around the eyes or mouth.

What are the risks of surgery?

Although your surgeon will remove as little tissue as possible, there are some general risks associated with surgery. Your doctor will discuss these, and any additional problems associated specifically with your situation.

- As tumors are often larger than their surface appearance indicates, the wound after the complete removal of the cancer may be larger than anticipated.

- We make every effort to obtain an optimal cosmetic appearance after surgery. With any excisional surgical procedure, scarring will occur at the site of removal.

- Occasionally, the surgical site may be slow to heal, grafts or flaps may fail, or the repair may re-open after closure. The most common risk factors for the include smoking, diabetes, bleeding, poor physical condition, or other disease processes.

- Skin cancer can involve nerves. With the removal of skin cancer, there may be local numbness or less common, loss of local muscle movement after the procedure.

- Occasionally, nearby nerves can be injured during the reconstruction of the defect following surgery. For sensory nerves, sensation will usually return over a time period of up to 24 months. Motor nerves are less likely to have a return of function. For damage to major nerves, microsurgical repair may be required to salvage function.

- No procedure can guarantee that the cancer will never come back. With Mohs surgery, however, your cure rate will be maximized. Previously treated tumors and large, longstanding tumors have the greatest chance of recurrence. Although infection is rare, it can occur. Make sure that you follow your wound care instructions carefully and care for your surgical site as directed.